To All Interested: I would invite you attention to a paper presented by Kenneth Bullington, "Radio Propagation at Frequencies Above 30 Meagcycles" in the October 1947 Proceedings of the I.R.E. - Waves and Electronics Section. Most all radio propagation prediction methods over the years have been based on the findings of his research for this paper. A GE Mobile Radio Data File Bulletin (10003-1), "VHF and UHF Propagation", was published in July 1962 for use by engineers and technicians for the prediction of radio coverage. Along with this bulletin a hard paper/plastic slide rule was manufactured by GE for its sales personnel to predict radio coverage. Motorola sales people liked to get a hold of it and use it also; "Range and Signal Strength Calculator for 2 Way Radio".There was a second version put together by GE in 1977; "Range and Transmitter Power Calculator". If you can find them, either of these slide rules can give adequate results with radio range calculations. With the general usage of computers in the 1980's many propagation programs appeared on the market, some use digitized USGA maps while others take a more simplistic approach. You get what you pay for! This Data File may be available on line, I am not sure if it is. Fred W5VAY
----- Original Message ----- From: ldgelectronics To: Repeater-Builder@yahoogroups.com Sent: Thursday, August 30, 2007 1:35 AM Subject: [Repeater-Builder] Re: Repeater Range : Estimate Program Available As a quick and dirty method, the radio horizon is: Distance (in miles) = Square Root of (2 * height in feet). Power and frequency do not really play that much into it. This has been mentioned in many stories of a repeater running just on the exciter and not many noticed. Once you get past the radio horizon, you cannot practically increase the power to get more distance. So a radio transmitting with an antenna on a 200 foot tower will give about 20 miles of coverage. VHF goes a little farther than UHF, but it's not by a lot. RadioMobile does a great job of factoring in many other things like TX power, RX sensitivity, frequency, coax and duplexer losses and some antenna modeling. After the learning curve, you can closely approximate typical systems with ease. Dwayne Kincaid WD8OYG > Ya I use it at work too. Its better than at least 1/2 of the commercial > products available. Quite amazing considering a Ham out of Quebec > programmed it. > > Jesse > > > > On 8/29/07, Nate Duehr <[EMAIL PROTECTED]> wrote: > > > > skipp025 wrote: > > > OK Groovy Guys and Gals, > > > > > > Is there a simple rule of thumb radio range versus frequency > > > and power level type computer program/software on the web? Maybe > > > some software that also considers generic repeater operation from > > > x-height agl with input frequency and power values. > > > > > > My friend doesn't need or really want a program with involved > > > graphics or Lat Long issues. Most of his Ham Radio work is > > > actually FM Simplex on flat ground and he's really interested > > > in using the program for both VHF High and Low Bands as a > > > very rough estimate of expected operational range (on flat > > > ground) in miles. > > > > > > Your turn... > > > > > > Thanks in advance... > > > > > > skipp > > > > Even though he doesn't need it, I think spending the effort to learn how > > to drive RadioMobile is time well spent, if you're into looking at > > paths, coverage, etc. > > > > For a free program, it's really not bad at all. And it'd give him > > something to "grow into" after he mastered the basics. > > > > Nate WY0X > > > > >
